[CmdletBinding()]
param(
    [ValidateSet('start', 'stop', 'restart', 'status')]
    [string]$Action = 'start',
    [string]$Listen = '0.0.0.0:18443',
    [switch]$MqttFallbackPlain
)

$ErrorActionPreference = 'Stop'
$Root = (Resolve-Path (Join-Path $PSScriptRoot '..')).Path
$RunDir = Join-Path $Root '.run\mock-edge-device'
$GoCache = Join-Path $Root '.gocache-mock-edge'
$Exe = Join-Path $RunDir 'mock-edge-device.exe'
$State = Join-Path $RunDir 'process.json'
$Stdout = Join-Path $RunDir 'stdout.log'
$Stderr = Join-Path $RunDir 'stderr.log'

function Read-State {
    if (-not (Test-Path -LiteralPath $State)) { return $null }
    try { return Get-Content -LiteralPath $State -Raw | ConvertFrom-Json } catch { return $null }
}

function Stop-Mock {
    $item = Read-State
    if ($null -ne $item) {
        $process = Get-Process -Id ([int]$item.pid) -ErrorAction SilentlyContinue
        if ($null -ne $process) {
            & taskkill.exe /PID ([int]$item.pid) /T /F 2>$null | Out-Null
            $process | Wait-Process -Timeout 5 -ErrorAction SilentlyContinue
        }
    }
    if (Test-Path -LiteralPath $State) { Remove-Item -LiteralPath $State -Force }
    Write-Host 'Mock edge device stopped.'
}

if ($Action -eq 'stop') { Stop-Mock; exit 0 }
if ($Action -eq 'status') {
    $item = Read-State
    if ($null -eq $item) { Write-Host 'Mock edge device is not managed.'; exit 0 }
    $process = Get-Process -Id ([int]$item.pid) -ErrorAction SilentlyContinue
    Write-Host ("PID {0}, listen {1}, {2}" -f $item.pid, $item.listen, $(if ($null -eq $process) { 'stopped' } else { 'running' }))
    exit 0
}
if ($Action -eq 'restart') { Stop-Mock }

New-Item -ItemType Directory -Path $RunDir -Force | Out-Null
New-Item -ItemType Directory -Path $GoCache -Force | Out-Null
Push-Location $Root
try {
	$env:GOCACHE = $GoCache
    & go build -o $Exe .\cmd\mock-edge-device
    if ($LASTEXITCODE -ne 0) { throw 'Mock edge device build failed.' }
} finally { Pop-Location }

$arguments = "-listen `"$Listen`" -data-dir `"$RunDir`""
if ($MqttFallbackPlain) { $arguments += ' -mqtt-fallback-plain' }
$process = Start-Process -FilePath $Exe -ArgumentList $arguments -WorkingDirectory $Root -RedirectStandardOutput $Stdout -RedirectStandardError $Stderr -PassThru
[ordered]@{ pid = $process.Id; listen = $Listen; started_at = (Get-Date).ToString('o') } | ConvertTo-Json | Set-Content -LiteralPath $State -Encoding UTF8
Start-Sleep -Milliseconds 500
if ($process.HasExited) { Get-Content -LiteralPath $Stderr -ErrorAction SilentlyContinue; throw 'Mock edge device exited during startup.' }
Write-Host "Mock edge device started (PID $($process.Id))."
Write-Host "Manual IP: use a non-loopback host IP with HTTPS port $($Listen.Split(':')[-1])."
Write-Host "Automatic discovery: UDP port 31001"
Write-Host "Pairing code: 246810"
Write-Host "Logs: $Stdout / $Stderr"